Chapter 9 Q & A Flashcards
what is the best extimate of the diameter or width of the sound beam as it exits the transducer
A 6 mm
B 9 mm
C 12 mm
D 8 mm
C
beam diameter at beginning is same as active element
what is the diameter of the sound beam at a depth of 8 cm
A 6 mm
B 9 mm
C 12 mm
D 8 mm
A
at end of near zone, beam diameter is one half width of the transducer diameter
what is the diameter of the sound beam at a depth of 16 cm
A 6 mm
B 9 mm
C 12 mm
D 8 mm
C
depth equal to 2 near zone lengths the beam diamter is same as the diameter of the active element
at what depth is the focus
A 6 cm
B 8 cm
C 1 cm
D 12 mm
B
focal depth is the same as the length of the near zone
what depth marks the beginning of the focal zone
A 6 cm
B 8 cm
C 12 mm
D 8 mm
A
focal zone is the region around the focus./ in this example the focal zone begins at a depth of 2 cm shallower than the focus
what depth marks the end of the focal zone
A 6 cm
B 8 cm
C 10 mm
D 10 cm
E 8 mm
D
the focal zone is the region around the focus. In this example the focal zone ends at a depth 2 cm deeper than the focus
at which of the following depths is the beam narrowing
A 6 cm
B 8 cm
C 12 cm
D 10 cm
E 12 cm
A
the beam narrows within the near zone
the only dpeth within the near zone is choice A
at whioch of the following is the beam widening
A 2 cm
B 4 cm
C 6 cm
D 8 cm
E 9.375 cm
E
the beam widens in the far zone.
the only depth within the far zone is choice E
at which of trhe following depths is the beam most likely to have the same diameter as it has at a depth of 11 cm
A 1 cm
B 3 cm
C 5 cm
D 8 cm
E 14 cm
C
think of the beam as being symmetrical around the focus. Thus the beam diameter will be similar when it is 3 cm shallower and 3 cm deeper than the focus
which of the following terms does not belong
A focus
B end of the near zone
C end of the fraunhofer zone
D middle of the focal zone
C
the end of the Fraunhofer zone is the end of the sound beam
a pair of 6 MHZ probes are identical except for the active element diameter. The active element diameters are 6 mm and 10 mm respectively. The sound beam of which probe will have a shallower focus
6 mm
smaller diameter crystals prodcue shallower foci
a pair of 9 mm diamter probes are identical except for freq. which is 3 MHz and 6 MHz respectively. which will have a shallower focus?
3 MHz has a shallower focus,
focal depth increases with freq
which of the following probes creates a beam with the depest focus
A 4 mm dia, 4 MHz
B 6 mm dia, 8 MHz
C 6 mm dia, 2 MHz
D 5 mm dia, 8 MHz
B
longer focal lengths are associated with larger diameter and higher freq
which of the following probes creates a beam with the shallowest focus
A 4 mm dia, 4 MHz
B 6 mm dia, 8 MHz
C 4 mm dia, 2 MHz
D 5 mm dia, 8 MHz
C
shorter focal lengths are associated with smaller diameter and lower freq
which of the folloing probres creates a beam with teh shallowest focus
A small dia, high freq
B large dia, high freq
C small dia, low freq
large dia, low freq
C
shorter focal lengths are associated with small diameter and low freq